A torque motor is typically used for operating the pilot stage of a two-stage electrohydraulic servovalve. German Offenlegungsschrift No. 3 501 836 (and corresponding U.S. Pat. No. 4,682,063) discloses a torque motor having an armature which is movably mounted between two opposed pole screws, which are threadedly mounted on a body. The pole screws carry electric control coils for influencing the magnetic field produced by a permanent magnet in the armature chamber. It is regarded as a disadvantage with this type of torque motor that two control coils are needed for moving the armature. First, a control circuit has to be provided for exciting both coils, which results in an increased space requirement. Secondly, this torque motor is made up of many parts, has a complicated structure, and is believed to be unreliable in operation, as the failure of one component may cause a malfunction of the whole system.